Supersaturated solid solution obtained by mechanical alloying of 75% Fe, 20% Ge and 5% Nb mixture at different milling intensities

Mechanical alloying process of Fe75Ge20Nb5 composition has been studied at different milling frequencies from initial pure powder mixture to the development of a single bcc phase (supersaturated solid solution). As an intermediate state, an intermetallic phase is formed, which disappears after further milling or after thermal treatment (ascribed to an endothermic process at 700-800 K). A preferential partition of Nb and Ge to the boundaries between nanocrystals of bcc Fe-Ge-Nb supersaturated solid solution is observed from X-ray diffraction (XRD) and Mössbauer results.